The present invention relates generally to an electrical discharge machining device, and more particularly to an oil bath of the electrical discharge machining device.
The work platform of the conventional electrical discharge machining device is located in the receiving compartment of an oil tank of the machining device. In operation, a workpiece is placed in the receiving compartment such that the workpiece and the process electrode are fully immersed in the process oil. Upon completion of the process, the process oil is drained to facilitate the removal of the workpiece from the oil tank. The oil tank is generally provided with an elevating mechanism comprising a plurality of hydraulic cylinders and pneumatic cylinders, which are located between the bottom of the oil tank and the base of the machining device. The bottom of the oil tank is provided with an axial hole for receiving a support shaft which is connected with the work platform. The oil tank is actuated by the cylinders to move up and down in relation to the work platform, so as to enable the work platform to emerge from the top of the oil tank to facilitate the disposing or the removing of the workpiece. The conventional oil tank elevating mechanism is defective in design in that the leak of the process oil is apt to take place unless the axial hole and the support shaft are airtightly sealed off with precision. In addition, the base of the conventional machining device is provided with additional facilities, such as the process oil storage tank, the process oil feeding pipe, and the process oil draining pipe, which take up additional space of the machine base and hinder the activity of a machine operator. In light of the-pipes being exposed, only the small pipes are suitable for use in feeding or draining the process oil at the expense of the feeding and the draining efficiencies.
It is the primary objective of the present invention to provide an electrical discharge machining device with a process oil tank elevating structure which is relatively simple in technique as compared with the prior art structure.
It is another objective of the present invention to provide an electrical discharge machining device with a, process oil tank elevating structure which is efficient in feeding and draining the process oil.
It is still another objective of the present invention to provide an electrical discharge machining device with a process oil tank elevating structure comprising the process oil storage tank, the process oil feeding pipe, and the process oil draining pipe, which are all concealed to minimize the overall volume of the machining device and to prevent them from impeding the activity of a machine operator.
The electrical discharge machining device of the present invention comprises a base, a support column, a process oil tank, a work platform, an oil feeding device, an oil drainage device, and a linear actuation device. The base has an oil storage compartment and an upright column. The support column is fastened at one end with the base and is located in the oil storage compartment. The oil tank has an open top and a drainage hole located at the bottom of the tank and dimensioned to dispose the support column therethrough. The work platform is fastened with other end of the support column and is located in the oil tank. The work platform is greater in area than the drainage hole. The drainage hole is connected with one end of a draining pipe which is connected at other end thereof with the oil storage compartment. The actuation device is mounted on the upright column and is connected with one side of the oil tank for actuating the oil tank to slide back and forth between an upper position and a lower position along the support column. As the oil tank is located at the upper position, the drainage hole is sealed off by the work platform, thereby allowing the oil tank to be filled with the process oil. When the oil tank is located at the lower position, the process oil is drained from the oil tank to the oil storage compartment via the draining pipe.
The machining device of the present invention is provided with a process oil feeding pipe which is put through the interior of the support column to be in communication with the oil storage compartment. The feeding pipe has an outlet end which is; located at the junction of the support column and the work platform such that the outlet end is in communication with the oil tank.